Chimping, is it just me?

[yelvertoft]

Originally Posted by bpw

You don’t say what tone your plane is and what colour your sky is? When thinking of planes I tend to think of a predominantly white plane against a blue sky, which would be fairly easy to check. A dark plane against a white sky, a white plane against a dark sky; both would be fairly straightforward also, I think.

In simple terms, if the plane were white, you’d expect to see spikes to the right of the histogram, but not up against the right edge, as this would represent overexposure. This would hold true whatever the colour of the sky. If the plane were black, you’d expect to see spikes to the left of the histogram, but not up against the left edge, as this would represent underexposure. Over or underexposure are both probably impossible to detect from the image alone.

I was actually thinking of this image:
http://www.worldphotographyforum.com...=500&ppuser=34

How can I tell from the histogram that I've got the exposure of the 'plane right? All the histogram is telling me is how many pixels I have at a particular tonal value. As long as I don't have a huge spike to the far left or far right then I can understand what you are saying. But this image, like many other similar shots, just has a peak somewhere in the middle. It can still be a peak in a different part of the middle section and be over or under exposed by probably 0.7 to 1.0 stops.

Advice?

Duncan

[bpw]

Very nice picture.

I would expect the white in this image to be represented by a short spike at the extreme right of the histogram. If the spike sits against the right-edge of the histogram then these areas are over-exposed and there will not be any detail recorded in the white areas. This may not be a problem, but if it were, I’d dial in some compensation and go again.

The same thing applies for dark areas at the left edge of the histogram. Sometimes I have to make a decision about which detail to lose, because it’s not always possible to record both light and dark areas with a contrasty subject in bright sunlight. However, if both extremes of the tonal range in this image are on the histogram, then I have a perfect exposure with detail in both areas.

This is only of any use, of course, when I have the time to do something about it. If this were the one and only pass of this plane, then you’ve got to go with your knowledge and experience. The other problem is that the lighting will change as the plane flies past, which will ideally require a different exposure, but these problems exist whether we use the histogram or not. This happens a lot in my type of photography too. Shooting RAW allows me to correct small errors in exposure, but if I haven’t recorded any detail in light areas of the image, no amount of processing can bring it back. I also like to get within 2/3 of the correct exposure, otherwise corrections result in excessive noise (that might be my old 10D sensor).

But I often find when photographing a bird that I have time to take a shot, check the histogram, make an adjustment (if necessary), and fire off some more shots. If inexperienced, this will, in some circumstances, change a poorly exposed shot into a very good one.

[Jon Sharp]

I think I'm taking this 'chimping' to the extreme - over the last couple of weeks I've only used my camera attached to and controlled by a laptop ... (I still managed to expose a couple wrong - thank goodness for the delete key!)

another reason for chimping, see
http://www.worldphotographyforum.com...8&limit=recent